High-end smartphones offer high-speed wireless connections -- but few mobile operators have made the infrastructure investments required to keep up with them. The arrival of cheaper phones with 300Mbps LTE capabilities may encourage that investment.

LTE chips with real-world download speeds over 100Mbps have become a standard feature on high-end smartphones, while smartphones costing under US$100 now include LTE chips, albeit slower ones.

Better cameras, screens and design have gotten most of the attention on this year's crop of high-end smartphones, but support for the latest versions of LTE, a rarity a year ago, has become a standard feature. Download speeds on the HTC One M9 and the LG G4 top out at 450Mbps on paper, while the Samsung Galaxy S6 is theoretically capable of 300Mbps.

The underlying technology allowing these feats is LTE-Advanced. It allows phones to simultaneously use radio channels in different frequency bands for greater throughput, a technique known as carrier aggregation.

Chipmakers such as Qualcomm are readying more affordable chips that will bring 300Mbps capabilities to mid-range phones too: Smartphones powered by the Snapdragon 618 and 620 are expected to arrive during the second half of the year.

In phones costing between $200 and $300 without a contract, Qualcomm's Snapdragon 615 is one of the most popular processors, so it seems reasonable that smartphones powered by its successors should cost about the same.

Of course, existing and future smartphones won't be able to take advantage of the bandwidth increase that LTE Advanced offers unless networks have been similarly upgraded, something that's likely to happen if carriers see increased demand.

At the end of April, 30 out of 393 commercial LTE networks offered speeds of up to 300Mbps, in countries including the U.K., Germany and South Korea, according to the Global mobile Suppliers Association (GSA). Nine 450Mbps networks were either in trial or being deployed, the GSA said.

Coverage at those speeds is still limited, even within the countries where it is available. For example, British mobile operator EE offers 300Mbps only in parts of central London and at the Wembley sports arena. There the real world speeds are up to 150Mbps, it said.

EE is lucky in that it has a large frequency allocation in which to deploy the technology. Other mobile operators simply don't have enough radio spectrum to do it.

But LTE smartphone development isn't just about providing higher speeds on expensive devices. There is also a growing demand for affordable products as the technology is being rolled out in developing countries.

On Monday, chip maker Marvell boasted that a SoC (system-on-chip) it developed is powering a $65 LTE smartphone from Chinese manufacturer XiaoLaJiao. In addition to LTE, the HongLaJiao phone has a quad-core processor, a 5-inch HD screen and an 8-megapixel camera. That you can buy a whole LTE smartphone for less than it costs to upgrade the storage on an iPhone or a Samsung Galaxy S is quite extraordinary.

In the U.S. and Europe, there isn't the range of sub-$200 smartphones with LTE that consumers in China and India can choose between. But products like the Motorola Moto E still offer good value for money, even though the specs aren't keeping up with new models from the likes of Xiaomi and Micromax.

These smartphones illustrate two closely related developments: the newfound affordability of LTE and the increasing competition between chip makers, which bodes well for the future. Today users pay a premium for LTE, but by next year that will likely be a thing of the past.

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